Snap beans（嘣豆）possess the good qualities of other beans, but they may be less well known. Snap beans are native to the Americas. They are harvested and served inside their covering, called a pod（豆莢）. Most kinds of snap beans are green, but some have yellow or purple pods.

Snap beans are picked when they are young. Fresh ones break in half with a sound like the snap of two fingers. But the pods and the beans inside are soft enough to cook easily and eat.

In the United States, there are different names for snap beans. Some people call them string beans（四季豆）. That is because earlier kinds had strings that had to be removed from the pods. Other names are green beans or wax beans, which are yellow.

Pole beans are closely related to other kinds of snap beans. Farmers grow these long, thin plants on sticks or poles for support. Some pole beans can be harvested up to ten times in a season. But pole beans require more labor. They are not easily harvested by machine like snap beans grown on short plants.

Snap beans have a short growing period, forty-five to sixty days. They are sold fresh, canned or frozen. They grow easily. But too much water in the soil will cause disease in the roots.

The soil should be loose. Snap beans should be planted in different areas from year to year to avoid disease carried in the soil. Like all beans and peas, snap beans release nitrogen（氮）into the soil. So they provide natural fertilizer.

The world crop is about one-thousand-five-hundred-million kilograms. France, Mexico, Iraq and Argentina are big producers. But the United States is the biggest producer and importer of snap beans. After years of decrease, Americans are again eating more of this traditional vegetable with their evening meal.

In the United States, the Agriculture Department says prices have moderately increased even while production has risen. American imports increase during the winter months. The top growing season is May through October.

Beans are naturally high in protein. But they provide higher quality protein when eaten with a grain like rice or wheat. Beans are also high in vitamins A, B and C. And they contain a lot of fiber, a vegetable material that many people do not get enough of in their diet.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.